One piece sheet metal trunnion (t-bolt)



Dec. 21, 1965 w. M. WILLIS 3,224,400

ONE PIECE SHEET METAL TRUNNIQN (T-BOLT) Filed July 2, 1962 58 INVENTOR 4 WILLIAM M. WILLIS 176 13 BY 6 M ATTORNEY United States Patent 3,224,400 ONE PIEE SHEET METAL TRUNNION (T-BOLT) William M. Willis, Northridge, Califi, assignor to Aeroquip Corporation, Jackson, Mich. Filed July 2, 1962, Ser. No. 206,912 2 Claims. (Cl. 113-116) The invention pertains to a method of forming T-members of one-piece construction having perpendicularly disposed interconnected tubular portions.

In the practice of the method of the invention, the T- members having intersecting tubular portions may be formed for use as a conventional pipe or conduit T-rnembers or for other T-member applications of this configuration. A T-mem-ber formmed in accord with the method of the application finds particular advantage as employed as a trunnion in a circumferential clamp construction of the type shown in U.S. Patent No. 2,395,745, and a portion of the description will be related to the advantages of forming clamp trunnion members in accord with the invention.

It is an object of the invention to provide a method of constructing a T-member having intersecting tubular portions from sheet stock. The sheet stock is drawn in a series of steps forming the final configuration of one of the tubular portions. Thereupon, a portion of the drawn blank is flattened, trimmed and formed to define the other tubular portion of the T-member. The method of construction is such that the first mentioned tubular portion is of a continuous wall construction having great resistance in the axial direction against compressive forces, and the other tubular portion is of a split configuration being defined by a pair of opposed longitudinally extending edges.

Another object of the invention is to provide an economical method of manufacturing a T-member of high strength characteristics which may be very accurately formed with a minimum of special forming equipment.

Another object of the invention is to provide a method for constructing a T-member from sheet material, having intersecting tubular portions wherein one of the tubular portions has a continuous wall and seams or splits are minimized in the construction.

A further object of the invention is to provide a method of manufacturing a cross member having intersecting tubular portions wherein the cross member is formed of a pair of T-members drawn and formed from sheet ma terial.

A further object of the invention is to provide a trunnion for a band-type clamp of T-construction having intersecting tubular portions, wherein one of the portions must resist axial compressive forces, and wherein the method of forming the trunnion aligns the molecules and stresses of the T-member in a manner which will effectively resist such compression.

These and other objects of the invention arising from the details of the method thereof will be apparent from the following description and accompanying drawings wherein:

FIG. 1 is a perspective, detail view of the band ends of a clamp with which the T-member trunnion, manufactured in accord with the method of the invention, may be employed,

FIGS. 2 through are views of the sequential forming of a T-mem-ber in accord with the invention, FIGS. 2, 3, and 7 through 10, being in perspective, and FIGS. 4, 5, and 6 being elevational, diametrical sections,

FIG. 11 is an enlarged, detail, elevational, sectional view of the partially closed end of the continuous wall tubular portion,

FIG. 12 is a perspective view of a cross member manufactured in accord with the method of the invention, and

FIG. 13 is a back, elevational view of the T-member of FIG. 10.

Basically, the invention is directed to a method of forming a T-member having perpendicularly disposed tubular, cylindrical portions, and the resultant T-mernber may be employed in the known manner of T-members in the plumbing, conduit, and mechanical arts. A particular application of the invention is as a trunnion in the circumferential clam-p art of the type shown by US. Patent No. 2,395,745, and the pertinent band structure of this type of clamp is shown in FIG. 1. For purposes of illustration, the method of the invention will be described in conjunction with the forming of a T-mem'ber for use as a trunnion with this type of band clamp.

Referring to FIG. 1, a band 10 is adapted to encompass the article to be clamped, and the band is provided with a pair of looped ends, wherein the folding of the ends back upon themselves forms eyes 12 and 14. The eyes may be maintained by spot-welding the folded back portion to the band portion. A tongue 16 is welded to the inside surface of one end of the .band to bridge that portion of the clamp defined by the tensioning bolt, whereby a full 360 of clamping action is provided. This construction will be apparent from the above-mentioned patent.

A T-bolt 18 having a threaded shank and a crosshead 20 received within the eye 12 provides the means for tensioning the clamp. The crosshead 20 is encompassed Within a bushing 22 and the eye 12 is bifurcated at 24 to permit the T-bolt shank to extend therethrough. Limited pivotal motion is permitted between the eye 12 and the crosshead 20. The eye 14 receives a T-shaped trunnion 25, FIG. 10, having a crossbearing portion 28 received within the eye, and the threaded shank extends through the neck 30 of the trunnion. A nut 32 threaded upon the bolt shank bears against the end of the trunnion neck 30 whereby tightening of the nut against the trunnion neck contracts the clamp band.

A T-member, manufactured in accord with the method of the invention, is initially formed of planar sheet stock represented by disk 34, FIG. 2. The sheet stock is placed in conventional drawing die apparatus which draws the planar stock into the cylindrical cup configuration of FIG. 3. In FIG. 3 the cup is shown inverted wherein a substantially planar closed end 36 is defined, and the cylindrical Wall is shown at 38. The edge 40 defines the opened end of the cup.

Referring to FIG. 4, the cylindrical cup is placed in successive draw dies wherein the cup is drawn to a cylindrical configuration having an enlarged cylindrical portion 42 and a small cylindrical portion 44 joined by a radially extending shoulder 46. Successive draw die operations reduce the cup configuration of FIG. 4 to that of FIG. 5 wherein the reduced diametrical portion 44 is now of the diameter desired of the neck 30 of the T-member and has a closed end 48. The cylindrical wall 42 is substantially of the same diameter as in FIG. 4. However, the radial dimension of the shoulder 46 has substantially increased from that of previous operations.

After the blank has been formed, as shown in FIG. 5, it is placed in a die which spreads the cylindrical wall portion 42 radially outwardly from edge 40, and the blank is then placed in a press whereby the outwardly spread wall portion 42 may be further deformed from the configuration of FIG. 6 to that of FIG. 7 wherein the portion 42 becomes coplanar with the radial shoulder 46. At this time the blank is of the form of FIG. 7, having a planar configuration 52 from which rises the tubular neck 30. At any stage after the completion of the diametrical forming of the tubular portion 30, FIG. 5, a hole 50 may be defined in the closed end 48 of the neck.

After the planar portion 52 is formed, it is trimmed by a shearing, milling, or other conventional shaping operation, to a rectangular configuration, as shown in FIG. 8, having opposed parallel edges 54 and 56. Thereupon, the planar portion 52 is deformed by a wrapping operation to define a substantially semicylindrical configuration, as shown in FIG. 9. Continued wrapping and forming results in the formation of a split tubular portion 58, having an axis perpendicularly disposed to the axis of the tubular neck 30. The seam of'the tubular portion 58 results from the opposed, adjacent relationship of the longitudinal edges 54 and 56. In the formation of a T-member for plumbing purposes, the seam 54-56 will be soldered or welded closed. Used as a trunnion member for the clamp of FIG. 1, it is not necessary to further process the edges 54 and 56, constituting the seam.

Using the T-member for plumbing purposes, threads may be defined upon the tubular portions adjacent the ends thereof, either internally or externally, as desired, or otherwise machined to accommodate the purpose for which they are intended.

In employing the T-member as a trunnion of the clamp of FIG. 1, a hole 62 is formed in the tubular portion 58 coaxially with the axis of the neck portion 30. As a trunnion, the tubular portion 58 becomes the bearing cross member 28. As a trunnion, the hole 50 defined in the end of the neck 30 is of lesser diameter than the internal diameter of the neck, whereby a radially, inwardly projecting flange 60 is formed at the Opened end of the neck. The cross member bearing tubular portion 28 may be received within the band eye 14 which is bifurcated at 64 to permit the neck 30 to extend therefrom. The threaded shank of the T-bolt 18 extends through the holes 62 and 50 and through neck 30, whereby the nut 32 may be threaded upon the shank for engagement with the flange 60 defined on the neck 30. Radial flange 60 provides a wear-resisting abutment surface for engagement with the nut 32 and, also, aids in uniformly distributing the compressive forces imposed upon the neck 30 by the nut and T-bolt. As the forces imposed upon the neck 30 during tightening of the nut 32 will be in an axial direction with respect to the neck, the drawing of the neck 30, being in the longitudinal direction, FIG. 5, will align the grain and stresses of the material of the neck in the longitudinal direction, providing a high resistance to bending from axial compressive forces being imposed on the neck.

If it is desired to form a cross member, the steps of the method through FIGS. 2 through 9 are similar to those described above. Upon the forming of the portion 52 in a semi-cylindrical form, as in FIG. 9, an identically formed member, indicated by primed references, is then welded or brazed to the other T-member such that the edges 54 and 56 of the two T-members are contiguous and the axes of the tubular portions 30 align. The resultant configuration will be that of FIG. 12. When the T-member or cross member, made in accordance With the invention, is employed for plumbing purposes, the closed end 48 of the neck 30 will be fully opened such that no inwardly extending flange 60 will be formed.

It will be appreciated that the invention provides a onepiece T-member having intersecting tubular portions wherein one of the tubular portions is provided with a continuous wall having high resistance to axial compressive forces, and the other tubular portion is formed with a longitudinally extending seam. Very little waste material is encountered in the forming of the T-member, and the method readily lends itself to high production manufacturing operations on automatic or semi-automatic equipment.

It is appreciated that various modifications to the method of the invention may be apparent to those skilled in the art, and it is intended that the invention be defined only by the following claims.

I claim:

1. The method of forming a trunnion for a clamp having first and second tubular cylindrical portions from sheet stock of uniform thickness wherein the stresses within the second tubular portion are so related as to resist axial compressive forces, comprising the steps of drawing a cylindrical tubular cup having a closed end from the sheet stock, forming the portion of said cup adjacent said closed end into a cylindrical tubular portion of reduced transverse dimension interconnected to the remaining larger cylindrical portion of the cup by a radially extending shoulder and concentrically related to said larger portion, flattening said larger cylindrical portion and shoulder to a planar configuration portion perpendicularly disposed to the longitudinal axis of said reduced cylin drical portion and trimming said planar portion to a rectangular configuration, said planar portion having side edges and end edges, and bending said planar portion to a tubular configuration in a direction parallel to said end edges substantially abutting said side edges to form said first tubular portion having an axis substantially perpendicular to the axis of said reduced portion, said reduced portion constituting said second tubular portion, forming a first hole in the closed end of said second tubular portion concentric to the axis thereof and forming a second hole in said first tubular portion coaxial with said first hole.

2. The method for forming a trunnion for a clamp as in claim 1, wherein said first hole is formed in the center of said closed end and of lesser diameter than said end wherein said hole is defined by an annular radially extending flange depending from said reduced tubular portion.

References Cited by the Examiner UNITED STATES PATENTS 1,602,265 10/ 1926 Hyman 29544 2,994,946 8/ 1961 Reynolds 1l3-46 FOREIGN PATENTS 124,822 6/ 1900 Germany. 805,844 3/1951 Germany.

CHARLES W. LANHAM, Primary Examiner.

MICHAEL V. BRINDISI, Examiner. 

1. THE METHOD OF FORMING A TRUNNION FOR A CLAMP HAVING FIRST AND SECOND TUBULAR CYLINDRICAL PORTIONS FROM SHEET STOCK OF UNIFORM THICKNESS WHEREIN THE STRESSES WITHIN THE SECOND TUBULAR PORTION ARE SO RELATED AS TO RESIST AXIAL COMPRESSIVE FORCES, COMPRISING THE STEPS OF DRAWING A CYLINDRICAL TUBULAR CUP HAVING A CLOSED END FROM THE SHEET STOCK, FORMING THE PORTION OF SAID CUP ADJACENT SAID CLOSED END INTO A CYLINDRICAL TUBULAR PORTION OF REDUCED TRANSVERSE DIMENSION INTERCONNECTED TO THE REMAINING LARGER CYLINDRICAL PORTION OF THE CUP BY A RADIALLY EXTENDING SHOULDER AND CONCENTRICALLY RELATED TO SAID LARGER PORTION, FLATTENING SAID LARGER CYLINDRICAL PORTION AND SHOULDER TO A PLANAR CONFIGURATION PORTION PERPENDICULARLY DISPOSED TO THE LONGITUDINAL AXIS OF SAID REDUCED CYLINDRICAL PORTION AND TRIMMING SAID PLANAR PORTION TO A RECTANGULAR CONFIGURATION, SAID PLANAR PORTION HAVING SIDE EDGES AND END EDGES, AND BENDING SAID PLANAR PORTION TO A TUBULAR CONFIGURATION IN A DIRECTION PARALLEL TO SAID END EDGES SUBSTANTIALLY ABUTTING SAID SIDE EDGES TO FORM SAID FIRST TUBULAR PORTION HAVING AN AXIS SUBSTANTIALLY PERPENDICULAR TO THE AXIS OF SAID REDUCED PORTION, SAID REDUCED PORTION CONSTITUTING SAID SECOND TTUBULAR PORTION, FORMING A FIRST HOLE IN THE CLOSED END OF SAID SECOND TUBULAR PORTION CONCENTRIC TO THE AXIS THEREOF AND FORMING A SECOND HOLE IN SAID FIRST TUBULAR PORTION COAXIAL WITH SAID FIRST HOLE. 